In a living room space where a plurality of air-conditioners are disposed, when an energy-saving control (e.g., a deactivation control for a certain time period) that suppresses power consumption on all of the air-conditioners is performed simultaneously, a temperature in the living room space may sharply rise, resulting in a poor environmental comfort.
Hence, a method or a system is disclosed which performs an energy-saving control for a predetermined time on each of the plurality of air-conditioners while shifting the time span of such a control with each other, thereby suppressing a sharp temperature rise (when being cooled) and a sharp temperature drop (when being heated) (see, for example, Patent Literatures 1 and 2). Accordingly, energy savings is accomplished, while at the same time, a certain environmental comfort is maintained.